Think of hydrogen as another type of battery, rather than an energy source. The issue is that it's not a very good battery. 

You start with electricity, you make hydrogen, you then use that hydrogen to make electricity again. Around one third of the energy you put in comes back out. This is not efficient and it also means hydrogen will be considerably more expensive than electricity for the customer. It’s better to just use the electricity in an electric machine or store it in a battery, if you can. 

There is potentially a role for hydrogen in heavy transport, steel and cement making etc where the advantages outweigh the inefficiencies, but even large mining operations are investing heavily in electric machines and many hydrogen trials have proven to be expensive and problematic.

Just as gas doesn’t need to play a role in our homes, hydrogen should not play a role in light vehicle transport. We don’t have a network of hydrogen stations, whereas we already have an electricity grid that spans most of the country and a growing number of solar installations where you can fill up your EV at home.

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Creating biogas from municipal waste or other waste streams is an interesting idea and a good example of a more circular economy, but so-called renewable gas is even more expensive than fossil gas and there's just not enough of it to make a dent. 

Some industries may need gas for a while as they transition to electric technologies, and we do use gas for electricity generation, but it is not a clean source of fuel, and it is certainly not renewable. A recently peer reviewed study has shown that it is even worse than coal for the climate due to its methane components, which is 80 times more potent than CO2 for warming. Gas definitely shouldn't be used in people's homes - it’s more expensive, it is running out, and burning it is bad for your health. Electric equivalents are more efficient, lower cost and much better for the environment. 

Around the world gas networks are shutting down because it’s clear the economics don’t stack up when compared to electricity. New houses should not be built with gas connections, because it locks families into decades of expensive, unhealthy gases in their home.

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Like highways, electricity lines are not always busy and have short periods of high demand. We will definitely need some grid upgrades to cope with the expected increase in demand as we electrify but, on average, our lines are at 30-40% capacity. So with smart demand management (like charging EVs or heating water during the day) and better pricing signals that encourage lower energy use and export at peak, we could increase that utilisation substantially without over-investing in new poles and wires, which will be paid for by customers over time on their bills. 

The more electricity generated by customers, the more hydro we can store for those winter peaks without the need to burn fossil fuels and the less need there will be for expensive, taxpayer funded upgrades of our network. Rooftop solar plays an important role here; when we have a dry year with not much rain, there are 5-10% more sunshine hours. 

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Batteries are are a crucial piece of the puzzle. While batteries are individually small, they add up. As an example, just 120,000 homes (or five percent of New Zealand households) with a medium-sized battery could potentially reduce the peak load as much as our largest hydro power station, Manapouri. While these batteries would not hold as much energy as Manapouri, they could output the same amount of power for an hour or two when the system really needs it. 

Every home with a battery basically removes themselves from peak, and it could potentially remove their neighbours from peak, too. 

Electricity use is also increasing in summer (largely due to air conditioning requirements and EVs) and this will have repercussions on lake levels in winter. Irrigation is also a major user of electricity in summer in some regions. Solar is well-suited to both of these cases as the electricity is usually required during the day when the sun is out, so more solar at home and on our farms can provide a lot of what we need with less strain on the grid and at the lowest cost.

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Demand flexibility is a crucial component of our energy system and all customers - whether large or small users - should be rewarded for reducing demand when required, or exporting at peak times. The recent Government Policy Statement on Electricity seems to back that view.

It’s total energy consumption, not electricity consumption, that is key to a sustainable future. We need to use less energy to do the same things, i.e. better efficiency. Electrification is the energy efficiency we’ve always been looking for - at both a small and large scale. 

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In our homes, switching to electric vehicles, hot water heating, space heating and cooking can reduce total household energy use by around 70% because heat pumps, induction stoves and EVs are on average 3-4 times more efficient at using energy than conventional fossil fuel machines. These homes will use more electricity but much less energy overall and this enhanced efficiency is where a lot of the savings come from.

Any reduction in electricity use above and beyond the main efficiency gain from electrification, whether through more efficient electric machines (e.g. LED light bulbs) or behaviour change (e.g. riding an e-bike instead of the EV) is a bonus, but electrification should come first to lock in the big-ticket emissions reduction and efficiency benefits.

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Even if electric homes get all their electricity from the grid rather than rooftop solar, they will still save a considerable sum compared to a fossil fuelled home. And generating your own electricity through rooftop solar brings those costs down further because it is consumed where it is produced. 

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The Commerce Commission decides how much the regulated monopolies can spend on upgrades and while bills are expected to rise to pay for those, Rewiring Aotearoa claimed a $1.2 billion win for consumers by arguing for more focus on the role customers could play. 

As an example, Mike Casey’s Forest Lodge orchard uses around 900% more electricity than the status quo because he has completely electrified all his farm machinery and now provides around 80% of that through solar generation and battery storage. The farm doesn’t use any additional electricity at peak times and that means there were no new poles or wires needed. 

A lot of the electricity we need for our increasingly electric lives could come from households, straight from the roof with no poles and wires in between. If that happens, it will actually reduce the need for expensive, taxpayer funded upgrades of our network. 

Like highways, electricity lines are not always busy and have short periods of high demand. On average, our lines are at 30-40% capacity, so with smart demand management (like charging EVs or heating water off-peak) and better pricing signals that encourage savings and export at peak, we could increase that utilisation substantially without over-investing in new poles and wires. 

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Australia has around 35% rooftop solar penetration, while New Zealand is at around 3%, but it is growing as more people realise it is the cheapest form of energy available to New Zealand households. New Zealand also has similar solar potential to the state of Victoria.

Even if we put a magical power plant in the middle of the country that generated free electricity, it would still be cheaper for customers to have rooftop solar panels because of the costs associated with all the poles and wires and the margins required for those businesses that provide it.

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We will need a lot more renewable energy in the future, but when they talk about big solar and wind farms, they only talk about electricity generation. Generation is less than half the total cost that customers pay. The price of distribution will still keep going up, no matter how much energy supply there is. Rooftop solar cuts out the middleman, by delivering energy from your roof straight into your home; no poles or wires needed, and therefore no distribution costs to pay.

Added to that, the price of grid electricity and fossil fuels is expected to keep going up, while solar basically locks in the price of electricity for decades. That’s why finance is such a key part of the puzzle in making rooftop solar affordable for all New Zealanders. The upfront costs are higher, but the savings are concrete; so we need to give everyone access to the finance to unlock the decades of cost savings and emission reductions.

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